Demos are a way of recording gameplay from within Daikatana.
Using Demos Edit
Enable the console, then type in record *your demo name here* in console. This will begin the recording of your demo. Typing stop in console will make your demo stop recording.
To play back a demo, type in Demoplay *your demo name here*.dem. This will play back your demo. Make sure to remove the asterisks.
Demos will load the map that the demo was recorded on, so playing back old demos may require downloading an old version of a map, or sometimes even downloading an earlier version of Daikatana.
Demos in Daikatana 1.3 Edit
In the Daikatana 1.3 community patch, a lot of the original maps have been edited with glow maps. Some demos can run on these maps, and sometimes the engine wont recognize the glow maps on the original, and won't play back older demos.
1.3 also offers a feature that automatically records demos upon joining a singleplayer or multiplayer game under a mapname_date format. The command for enabling this feature is cl_demo_autorecord.